FIG. 13 is a front view of prior art thrust washer 300. During operation of a torque converter (not shown), thrust is generated on a hub for the converter, causing the hub to contact a cover for the torque converter. To prevent excessive wear between the hub and cover a thrust washer, for example, thrust washer 300, is disposed between the hub and the cover. At the same time, fluid circuits must be provided in the torque converter for cooling fluids, such as oil. An adequate flow of fluid is necessary to change and maintain fluid pressures in the torque converter, necessary for adequate clutch capacity and clutch controllability. The thrust washer blocks some of the necessary fluid circuits, and so, provision must be made to allow fluid to pass between the inner and outer circumferences 302 and 304, respectively, of washer 300. To accomplish this flow, it is known to provide slots 306 in surface 308 of washer 300. Typically, surface 308 is the surface that will contact the cover noted supra.
Unfortunately, slots 306 create discontinuities in surface 308, which increase wear on the thrust washer. Increased wear results in a shorter life for the thrust washer, which can affect the effective life and/or maintenance required for the converter. Increased wear also can increase parts costs by requiring that the washer be made of more expensive, wear-resistant materials.
Thus, there is a long-felt need for a thrust washer that can provide adequate fluid through flow while maximizing the surface area of the washer.